It’s about time that somebody came up with a proper explanation for Twitter. McSweeny’s nails it:

Twitter seems to be, first and foremost, an online haven where teenagers making drugs can telegraph secret code words to arrange gang fights and orgies. It also functions as a vehicle for teasing peers until they commit suicide.

There is also a succinct explanation for the ‘fail whale’:

Twitter is electric/computerized and available at all times, except when sexual misconduct and murder are “over capacity.” During these times, teen drug makers see a picture of a dead whale alerting them to bad energy.

UPDATE: On a similar theme, “Keith Starky Explains Twitter“.